Tumbling mill

ABSTRACT

A TUMBLING MILL IS PROVIDED FOR USE IN GRIDING, PULVERIZING AND POLISHING VARIOUS MATERIALS. THE MILL IS ADAPTED TO GENERATE A MULTIPLICITY OF MOTIONS. A MILL CHAMBER ROTATES ABOUT A HORIZONTAL AXIS AROUND A CLOSED, UNDULATING TRACK MOVING RADIALLY IN AND OUT WITH RESPECT TO A VERTICAL DRIVING AXIS, WHICH DRIVING AXIS ITSELF RECIPROCATES VERTICALLY CAUSING THE CHAMBER TO TILT ABOUT ITS HORIZONTAL AXIS.

Oct. 5, 1971 Q FOSTER EI'AL 3,609,921

TUMBLING MILL Filed Jan. 9, 1970 2 Sheets-Sheet 1 INVENTD RS.

CECIL A. FOSTER GEORGE W. BOOTH IYWM' mkot ATTORNEYS Oct. 5, 1971 c. A.FOSTER EI'AL 3,609,921

TUMBLING MILL Filed Jan. 9, 1970 2 Sheets-Sheet 2 INVENTORS.

CECIL. A. FOSTER GEORGE W. BOOTH ATTORN EYS United States Patent O3,609,921. TUMBLING MILL Cecil A. Foster, 25 Fairmount Ave., Johnston,RJ. 02919, and George W. Booth, West Main St, West Barnstable, Mass.02630 Filed Jan. 9, 1970, Ser. No. 1,585

Int. Cl. B24b 31/02 US. Cl. 51-164 8 Claims ABSTRACT OF THE DISCLOSURE Atumbling mill is provided for use in grinding, pulverizing and polishingvarious materials. The mill is adapted to generate a multiplicity ofmotions. A mill chamber rotates about a horizontal axis around a closed,undulating track, moving radially in and out with respect to a verticaldriving axis, which driving axis itself reciprocates vertically causingthe chamber to tilt about its horizontal axis.

BACKGROUND OF THE INVENTION (1) Field of the invention This inventionrelates generally to tumbling mills and more particularly is directedtowards a tumbling mill of improved design and efficiency having amultiplicity of motions from a single rotary drive.

(2) Summary of the prior art Tumbling mills generally are comprised of ashell or drum rotating about a horizontal axis. Whatever material is tobe reduced in size is fed into one end of the mill along with a chargeof a suitable grinding medium such as iron balls or the like. As themill rotates the material and the grinding medium tumble against oneanother in a cooperating action which grinds, polishes or pulverizes thematerial. Mills of this type customarily have very limited motions andas a result require a relatively long period of operation in which toachieve the desired grinding action.

Accordingly, it is an object of the present invention to provideimprovements in tumbling mills. Another object of this invention is toprovide a simple, low most tumbling mill having a multiplicity ofmotions adapted to increase the grinding, speed and efliciency of theappar'atus.

SUMMARY OF THE INVENTION This invention features a tumbling millcomprising a vertical drive shaft axially reciprocating a pivoted,telescoping horizontal rod connected to the vertical drive shaft and toa chamber mounted for rotation about the horizontal axis on anundulating, generally circular closed track. A variable speed motor isconnected to the drive shaft causing the chamber to rotate about ahorizontal axis, cyclically tilting about that axis while movingupwardly, downwardly and radially in and out as it operates.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of atumbling mill made. according to the invention,

FIG. 2 is a fragmentary sectional view in side elevation thereof, and,

FIG. 3 is a detailed sectional view showing the connection between thechamber portions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to thedrawings, the reference character generally indicates a base for atumbling mill, the base being comprised of a lower bed plate 12supporting a platform 14 by means of upright posts 16. The platform, inturn, supports a closed track 18 in the form of a cylindrical rod, whichin top plan view as shown in FIG. 1, is in the form of a distortedcircle somewhat flattened on four sides and which undulates in avertical plane as best shown in FIG. 2. The track 18 is supported on theplatform 14 by means of spaced ribs 20.

Extending up through the center of the base and platform is a driveassembly comprised of a drive shaft 22 rotatably mounted in a lowerbearing 24 fixed to the bed plate 12. The shaft 22 drivingly engages apulley 26 connected by a belt 28 to a variable speed motor and reductiongear assembly 30 located to the side of the unit. The shaft 22 engages acoupling 32 which in turn engages a drive shaft 34 rotatably mounted ina bearing 36 supported by cross pieces 38 to the platform 14. Drivinglyconnected to the shaft 34 is a cam 40 engaging a follower 42 mounted toa shaft 44 telescoped over the shaft 34. Thus, as the shaft 22 isrotated by the variablespeed motor, shaft 44 will also rotate about thevertical axis while at the same time undergoing vertical reciprocationas a result of the interaction between the cam and follower 40 and 42.

Mounted to the top of the shaft 24 is a hinge coupling 46 engaging theinner end of a connecting rod 48 normally disposed in the horizontalplane and provided at its outer portion with a tubular member 50telescoped over the inner end of a tie rod 52. The tie rod 52 isprovided with a coil spring 54 trapped between a bushing 56 secured tothe member 50 and an annulus 58 on the inner end of the tie rod 52. Thearrangement provides a spring-loaded sliding connection between the rods48 and 52 which also permits the rod 52 to rotate freely with respect tothe rod 48.

Mounted to the outer end of the tie rod 52 is a rotatable chamber 60secured to the rod in the illustrated embodiment by means of a screw 62passing through an opening in the end wall of the chamber and isthreaded to the tapped end of the rod 52. A boss 64 is formed at the endof the chamber for reinforcement thereof at the connecting joint.

The chamber 60, in the preferred embodiment, has an ovoidalconfiguration and is comprised of a pair of separable sections 66 and'68 connected to one another at the center. The chamber sections 66 and68 are circular in cross section and each is formed with cooperatingcontoured flanges 70 and 72 which come together to form annular groove74 adapted to fit over and roll about the track 18. The flanges oneither side of the groove extend out for some distance from the chamberwalls to encompass the track 18 and to insure that the chamber remainson the track even at high rotational speeds. The chamber halvesdetachably connect to one another by means of cooperating threads 76formed at the center line behind the annular groove 74. Other lockingarrangements obviously may be provided to permit the chamber to beopened and closed for easy loading and unloading of the charge ofmaterial and the grinding medium.

In the illustrated embodiment, the interior walls of the chamber 60 arelined with a stratum 78 of rubber or other resilient material which notonly lowers the noise level of the unit in operation but also aids inthe grinding action since it enhances the bouncing of loose materialwithin the chamber. The grinding action may be further enhanced byadding abrasive material to the liner 78. The abrasive can be coatedover the surface of the resilient liner as by spraying the same togetherwith a binder onto the liner. Also, abrasive inserts may be set into theresilient layer with the outer portions of the inserts either flush withthe surface of the liner or protruding therefrom to interact with thecharge of material in the chamber. Also, polishing agents may be placedin the chamber either in the form of dry material or suspended in aliquid as best suited for the particular task.

' The hinge mounting of the rod 48 permits the chamber 60 to be raisedfrom the horizontal position illustrated into a vertical or nearlyvertical position for loading and unloading purposes. When loading, thechamber is raised to the vertical position, the chamber section 66 isunscrewed from the section 68 and the charge of material as well as thegrinding medium are deposited in the raised section 68. The section 66is then screwed .back into position and the chamber lowered to thehorizontal position with the groove 74 placed over the track, the weightof the chamber together with its charge being sufficient frictionalforce to insure rotation of the chamber as it moves about the track. Thechamber not only will rotate but will tilt about its axis by reason ofthe .cam and follower 40 and 42 and the undulating rail 18.

Furthermore, the chamber will move radially in and out to add anothermotion component by reason of the flattened configuration of the track.The added motions enhance the polishing and grinding action and speed upthe processing on the charge. The operation can be further acceleratedby speeding up the motor drive as required.

Having thus described the invention What we claim and desire to obtainby Letters Patent of the United States is:

1. A tumbling mill, comprising: (a) a container adapted to receive acharge of material, (b) an irregularly contoured generally horizontalclosed track adapted to support and guide said container, (0) an annularmember mounted to said container for rolling engagement with said track,(d) a vertical drive shaft extending centrally through said track, (e)an extensible member connecting said shaft to said container wherebysaid chamber will be rolled about said track upon rotation of saidshaft, and

(f) drive means engaging said shaft.

2. A tumbling mill according to claim 1 including means for axiallyreciprocating at least a portion of said drive shaft to cause saidcontainer to tilt about its axis upon rotation thereof. 7

3. A tumbling mill accordingtolclairn 1 wherein said extensible memberis pivoted to .said drive shaft.

4. A tumbling mill according to claim 1 wherein said track is in theform of an undulating flattened circle.

5. A tumbling mill according to claim 1 including a stratum of resilientmaterial over the inner walls of said container.

6. A tumbling mill according to claim 5 including an abrasive mediumbonded to said stratum. I

7. A tumbling mill according to claim 1 wherein said extensible memberincludes a pair of relatively rotatable, spring-loaded elongated memberstelescopically connected to one another. i

'8. A tumbling mill according to claim 1 wherein said container is ofovoidal configuration comprised of a pair of matching cooperatinghalf-sections detachably connected to one another. 7

References Cited UNITED STATES PATENTS 2,135,839 11/1938 Persons 23325 X2,961,703 11/ 1960 .Pinotti.

1,895,622 1/1'933 Hannon 5l-,164 X 3,503,157 3/1970 Harper 51-164 HAROLDD. WHITEHEAD, Primary Examiner U.S. Cl. X.R.

